package cn.itcast.hotel.service.impl;

import cn.itcast.hotel.mapper.HotelMapper;
import cn.itcast.hotel.pojo.Hotel;
import cn.itcast.hotel.pojo.HotelDoc;
import cn.itcast.hotel.pojo.PageResult;
import cn.itcast.hotel.pojo.RequestParams;
import cn.itcast.hotel.service.IHotelService;
import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.core.incrementer.IKeyGenerator;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;

import javax.naming.directory.SearchResult;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {

    @Autowired
    private RestHighLevelClient client;

    @Override
    public PageResult search(RequestParams params) {

        try {
            //1,准备Request
            SearchRequest request = new SearchRequest("hotel");
            //2,准备DSL
            //2.1 query
            buildBasicQuery(params,request);

            //2.2 分页 (分页查询为.from)
            int page = params.getPage();
            int size = params.getSize();
            request.source().from((page - 1) * size).size(size);

            //2.3 排序
            String location = params.getLocation();
            if (location != null && !location.equals("")){
                request.source().sort(SortBuilders
                        .geoDistanceSort("location",new GeoPoint(location))
                        .order(SortOrder.ASC)
                        .unit(DistanceUnit.KILOMETERS)
                );

            }

            //3,发送请求，得到相应
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);

            //4,解析响应
            return handleResponse(response);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }


    }

    @Override
    public Map<String, List<String>> filters(RequestParams params) {
        try {
            //1，准备Request
            SearchRequest request = new SearchRequest("hotel");

            //2，准备DSL
            //2.1 query
            buildBasicQuery(params,request);

            //2.2 设置size
            request.source().size(0);

            //2.3 聚合
            buildAggregation(request);


            //3，发出请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);

            //4，解析结果
            Map<String ,List<String>> result = new HashMap<>();
            Aggregations aggregations = response.getAggregations();

            //4.1 根据品牌名称，获取品牌结果
            List<String> brandList = getAggByName(aggregations,"brandAgg");
            result.put("品牌",brandList);

            //4.1 根据品牌名称，获取品牌结果
            List<String> cityList = getAggByName(aggregations,"cityAgg");
            result.put("城市",cityList);

            //4.1 根据品牌名称，获取品牌结果
            List<String> starList = getAggByName(aggregations,"starAgg");
            result.put("星级",starList);

            return result;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public List<String> getSuggestions(String prefix) {
        try {
            //1，准备Request
            SearchRequest request = new SearchRequest("hotel");
            //2，准备DSL
            request.source().suggest(new SuggestBuilder().addSuggestion(
                    "suggestions",
                    SuggestBuilders.completionSuggestion("suggestion")
                            .prefix(prefix)
                            .skipDuplicates(true)
                            .size(10)
            ));
            //3，发起请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            //4，解析结果
            Suggest suggest = response.getSuggest();
            //4.1 根据补全查询名称，获取补全结果
            CompletionSuggestion suggestions = suggest.getSuggestion("suggestions");
            //4.2 获取options
            List<CompletionSuggestion.Entry.Option> options = suggestions.getOptions();
            //4.3 遍历
            ArrayList<String> list = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option : options){
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }





    private static List<String> getAggByName(Aggregations aggregations,String aggName) {
        //4.1 根据聚合名称获取聚合结果
        Terms brandTerms = aggregations.get(aggName);

        //4.2 获取buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();

        //4.3 遍历
        List<String> brandList = new ArrayList<>();
        for (Terms.Bucket bucket : buckets){
            //4.4 获取key
            String key = bucket.getKeyAsString();
            brandList.add(key);
        }
        return brandList;
    }

    private static void buildAggregation(SearchRequest request) {
        //2.2 聚合
        request.source().aggregation(AggregationBuilders
                .terms("brandAgg")
                .field("brand")
                .size(100)
        );

        request.source().aggregation(AggregationBuilders
                .terms("cityAgg")
                .field("city")
                .size(100)
        );

        request.source().aggregation(AggregationBuilders
                .terms("starAgg")
                .field("starName")
                .size(100)
        );
    }

    private void buildBasicQuery(RequestParams params,SearchRequest request) {
        // 构建BooleanQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 关键字搜索
        String key = params.getKey();
        if (key == null || "".equals(key)){
            //无条件，进行全查询
            boolQuery.must(QueryBuilders.matchAllQuery());
        }else {
            boolQuery.must(QueryBuilders.matchQuery("all",key));
        }


        //条件过滤
        // 城市条件
        if (params.getCity() != null && !params.getCity().equals("")){
            boolQuery.filter(QueryBuilders.termQuery("city", params.getCity()));
        }

        // 品牌条件
        if (params.getBrand() != null && !params.getBrand().equals(" ")){
            boolQuery.filter(QueryBuilders.termQuery("brand", params.getBrand()));
        }

        // 星级条件
        if (params.getStarName() != null && !params.getStarName().equals(" ")){
            boolQuery.filter(QueryBuilders.termQuery("starName", params.getStarName()));
        }

        // 价格
        if (params.getMinPrice() != null && params.getMaxPrice() != null){
            boolQuery.filter(QueryBuilders
                    .rangeQuery("price")
                    .gte(params.getMinPrice())
                    .lte(params.getMaxPrice()));
        }

        //2 算分控制
        FunctionScoreQueryBuilder functionScoreQuery = QueryBuilders
                .functionScoreQuery(
                        // 原始查询，相关性算分的查询
                        boolQuery,
                        // function score的数组
                        new FunctionScoreQueryBuilder
                                //其中的一个function score元素
                                .FilterFunctionBuilder[]{
                                        new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                                //过滤条件
                                                QueryBuilders.termQuery("isAD",true),
                                                //算分函数
                                                ScoreFunctionBuilders.weightFactorFunction(10)
                                        )
                        });

        request.source().query(functionScoreQuery);
    }

    private PageResult handleResponse(SearchResponse response) {
        //4 解析响应
        SearchHits searchHits = response.getHits();

        //4.1 获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("获取到"+ total +"条数据");

        //4.2 文档数组
        SearchHit[] hits = searchHits.getHits();

        //4.3 遍历
        List<HotelDoc> hotels = new ArrayList<>();
        for (SearchHit hit : hits){
            //获取文档source
            String json = hit.getSourceAsString();
            //反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);

            //获取排序值
            Object[] sortValues = hit.getSortValues();
            if (sortValues.length > 0){
                Object sortValue = sortValues[0];
                hotelDoc.setDistance(sortValue);
            }
            hotels.add(hotelDoc);
        }
        //4.4 封装返回
        return new PageResult(total,hotels);
    }
}
